Sip Server Name Resolution; Sip Server Name Resolution Configuration - Yealink SIP-T2 Series Administrator's Manual

Administrator's Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
Permitted
0, Integer from 60 to 65535
Values
Default -1, the IP phone will invoke "account.X.sip_server.Y.failback_timeout" to take effect.
account.X.outbound_proxy.Y.failback_sub-
Parameter
scribe.enable
It enables or disables the IP phone to retry to re-subscribe after registering to the secondary outbound
proxy server with different IP addresses when encountering a failover.
Description
Note: It works only if "account.X.outbound_proxy.Y.failback_mode" is set to 1, 2 or 3.
0-Disabled
Permitted
1-Enabled, the IP phone will immediately re-subscribe to the secondary outbound proxy server, for ensur-
Values
ing the normal use of the features associated with subscription (for example, BLF, SCA).
Default -1, the IP phone will invoke "account.X.sip_server.Y.failback_subscribe.enable" to take effect.
Parameter account.X.sip_server.Y.outbound_proxy_enable
It enables or disables the IP phone to use outbound proxy server address configured by "accoun-
t.X.outbound_proxy.Y.address".
Description
Note: It works only if "account.X.outbound_proxy_enable" is set to 1 (Enabled).
Permitted
0-Disabled
1-Enabled
Values
Default 1
[1]
X is the account ID. For T54S/T48S/T48G/T46S/T46G/T29G, X=1-16; for T52S/T42G/T42S, X=1-12; for T41P/T41S/T27G,
X=1-6; for T40P/T40G/T23P/T23G, X=1-3; for T21(P) E2, X=1-2; for T19(P) E2/CP920, X=1.
[2]
Y is the server ID. Y=1-2.

SIP Server Name Resolution

If a domain name is configured for a server, the IP address(es) associated with that domain name will be resolved
through DNS as specified by
to adapt to various deployment environments. The IP phone performs NAPTR query for the NAPTR pointer and trans-
port protocol (UDP, TCP and TLS), the SRV query on the record returned from the NAPTR for the target domain name
and the port number, and the A query for the IP addresses.
If an explicit port (except 0) is specified, A query will be performed only. If a server port is set to 0 and the transport
type is set to DNS-NAPTR, NAPTR and SRV queries will be tried before falling to A query. If no port is found through
the DNS query, 5060 will be used.
Topic

SIP Server Name Resolution Configuration

SIP Server Name Resolution Configuration
The following table lists the parameters you can use to configure SIP server name resolution.
Parameter account.X.sip_server.Y.transport_type
Description It configures the type of transport protocol.
Permitted 0-UDP
212
[1][2]
RFC 3263. The DNS query involves NAPTR, SRV and A queries, which allows the IP phone
[1][2]
<MAC>.cfg
[1][2]
<MAC>.cfg
<MAC>.cfg